Hello Prad
The info command will give you details of a function - its type
signature and the module where it is defined, its fixity if it is an
infix function:
Prelude> :info length
length :: [a] -> Int -- Defined in GHC.List
The shorthand is :i
Prelude> :i (>>=)
class Monad m where
(>>=) :: m a -> (a -> m b) -> m b
...
-- Defined in GHC.Base
infixl 1 >>=
For constructors, info will tell you which data type the constructor
belongs to and the module where it is defined:
Prelude> :i Just
data Maybe a = ... | Just a -- Defined in Data.Maybe
There is no mechanism like docstring in Haskell though - the
information displayed by the info command is not customizable.
Best wishes
Stephen